K61P144M120SF3 Datasheet, PDF (72/82 Pages) Freescale Semiconductor, Inc – K61 Sub-Family Data Sheet

Dimensions
6.9.1 TSI electrical specifications
Table 51. TSI electrical specifications
Symbol Description
V_DDTSI Operating voltage
C_ELE Target electrode capacitance range
f_REFmax Reference oscillator frequency
f_ELEmax Electrode oscillator frequency
C_REF Internal reference capacitor
V_DELTA Oscillator delta voltage
I_REF Reference oscillator current source base current
• 1uA setting (REFCHRG=0)
• 32uA setting (REFCHRG=31)
I_ELE Electrode oscillator current source base current
• 1uA setting (EXTCHRG=0)
• 32uA setting (EXTCHRG=31)
Pres5 Electrode capacitance measurement precision
Pres20 Electrode capacitance measurement precision
Pres100 Electrode capacitance measurement precision
MaxSens Maximum sensitivity
Res Resolution
T_Con20 Response time @ 20 pF
I_{TSI_RUN} Current added in run mode
I_{TSI_LP} Low power mode current adder
Min.
1.71
1
—
—
TBD
TBD
—
—
—
—
—
—
—
0.003
—
8
—
—
Typ.
—
20
8
0.5
1
600
1.133
36
1.133
36
8.3333
8.3333
8.3333
12.5
—
15
55
1.3
Max.
3.6
500
TBD
TBD
TBD
TBD
1.5
50
1.5
50
38.4
38.4
38.4
—
16
25
—
TBD
Unit
V
pF
MHz
MHz
pF
mV
μA
μA
pF/count
pF/count
pF/count
fF/count
bits
μs
μA
μA
Notes
1
2
2
2
2, 3
2, 4
5
6
7
8
9
10
1. The TSI module is functional with capacitance values outside this range. However, optimal performance is not guaranteed.
2. Fixed external capacitance of 20 pF.
3. The programmable current source value is generated by multiplying the SCANC[REFCHRG] value and the base current.
4. The programmable current source value is generated by multiplying the SCANC[EXTCHRG] value and the base current.
5. Measured with a 5 pF electrode, reference oscillator frequency of 10 MHz, PS = 128, NSCN = 8; Iext = 16.
6. Measured with a 20 pF electrode, reference oscillator frequency of 10 MHz, PS = 128, NSCN = 2; Iext = 16.
7. Measured with a 20 pF electrode, reference oscillator frequency of 10 MHz, PS = 16, NSCN = 3; Iext = 16.
8. Sensitivity defines the minimum capacitance change when a single count from the TSI module changes, it is equal to (C_ref
* I_ext)/( I_ref * PS * NSCN). Sensitivity depends on the configuration used. The typical value listed is based on the following
configuration: Iext = 5 μA, EXTCHRG = 4, PS = 128, NSCN = 2, I_ref = 16 μA, REFCHRG = 15, C_ref = 1.0 pF. The minimum
sensitivity describes the smallest possible capacitance that can be measured by a single count (this is the best sensitivity
but is described as a minimum because it’s the smallest number). The minimum sensitivity parameter is based on the
following configuration: I_ext = 1 μA, EXTCHRG = 0, PS = 128, NSCN = 32, I_ref = 32 μA, REFCHRG = 31, C_ref= 0.5 pF
9. Time to do one complete measurement of the electrode. Sensitivity resolution of 0.0133 pF, PS = 0, NSCN = 0, 1
electrode, EXTCHRG = 15.
10. REFCHRG=0, EXTCHRG=4, PS=7, NSCN=0F, LPSCNITV=F, LPO is selected (1 kHz), and fixed external capacitance of
20 pF. Data is captured with an average of 7 periods window.
7 Dimensions
K61 Sub-Family Data Sheet Data Sheet, Rev. 3, 2/2012.
72
Preliminary
Freescale Semiconductor, Inc.